argument can be either "pedantic" or "old" (actually, or anything
else). In case of "pedantic" mode, use -ansi -pedantic compilation
flags. Fix the build to compile in pedantic mode. (Version 3 of
the patch, with after-review fixes)
never defined.
It was used at some point to add -Wuninitialized to debug flags,
but not any more. If there is still need to add -Wunitialized,
it can be added directly to $global_warnings.
